Patent GB-763832-A (GB)
Title: Improvements in sheet-separating machines
Inventor: TEBBS GEORGE WILLIAM
IPC: B65H1/18
Filed: 1953-06-01
Abstract: 763,832. Feeding sheets. BACKHOUSE, H. T. Sect. 1, 1954 [June 1, 1953], No. 15168/53. Class 100(1) Pile-raising apparatus. Pile elevating means for a sheet-separating machine comprises two pile supports guided for up and down movement normally one above the other, and each operable to support a pile independently of the other, an upwardly extending elongated elevating member or two such members operable to elevate each the pile supports at a rate to maintain the top of the pile supported thereby at a substantially constant height as the sheets are removed from the top of the pile, releasable means for clutching each of the supports to the elevating member or members to be raised thereby and manually operable means whereby each support may, on release from the elevating member, be moved up or down relative to it, so that the lower support may be lowered to receive a new pile and then raised to enable it to. be transferred to the upper support. As shown in Fig. 3 the pile supports 21, 22 each comprise a pair of brackets joined by cross members 24 and each bracket is connected to a channel shaped guide 28 slidable up and down a vertical square-section pillar 20. The guides for the upper support 21 are on the outside of the pillars 20 and those for the lower support 21 are on the inside. Also the brackets of the lower support 21 are spaced a smaller distance apart than the brackets of the upper support so that the supports can pass one another when necessary. Endless chains 32 on each side of the apparatus pass over sprockets 33 at the upper end and guides 34 at the lower. In addition a support plate 35 prevents movement (to the right in Fig. 3) of the left-hand lap. of the chain. Each pair of guides 28 carries a cross shaft 38 on which are mounted sprockets engaging the left hand laps of chains 32. At one end each shaft 38 carries a ratchet wheel 44 which co-operates. with a locking pawl 42. A handle 46 is provided on each shaft 38 which can be pressed inwardly to displace the ratchet wheel 44 out of engagement with the pawl 42 and then rotated to cause the support to climb up or down the elevating chains 32. Normally the shaft is held by the pawl 42 against rotation so that the supports are raised at the same speed as the chain 32. The chain is moved by rotation of the sprocket 33 at a rate such that the top of the pile remains at a substantially constant height. This is effected by the feeler which is repeatedly moved down on to the top of the pile by a cam mechanism acting through a spring. An abutment'connected to move with the feeler is adapted to displace a horizontal rail 75, Fig. 5 running along one side of the top of the pile and movable up and down. A hooked extension 75a at one end of the rail co-operates with a pin 81 on an arm 82 rotatable about a pivot 83 and spring urged to the left. A ratchet wheel 86 on shaft 87 carrying sprockets 33 is operable by a pawl 84 carried by a lever 88 oscillated about the shaft 87 by a cam 90. The pawl is normally biased out of engagement with the ratchet. When the top of the pile falls below a certain level the feeler causes the rail 75 to be depressed so that the hook 75a releases pin 81. This allows the arm 82 to swing against the pawl and move it into engagement with the ratchet. On the next oscillation of lever 88 the shaft 87 is rotated to advance the chains 32. The arm 82 is reset, when the pile is sufficiently raised, by abutment between lever 88 and a pin 92 on the arm. The upper pile support brackets have spring operated latches adapted to snap past and engage the edges of the pile board carried by the lower pile support. Adjustable stacking guides 100, 102, Fig. 3 fixed to a stationary member project up through slots in a pile board carried on the lower support to assist in building up a pile on the board. In operation, a pile board is placed on the lower brackets and a pile of sheets is built on it. The brackets are then raised by rotation of the handle 46 to bring the top of the pile to working height after which the pile is elevated automatically by the chains. At a convenient stage the upper brackets are lowered manually to engage the latches under the pile board and then raised to take the weight of the pile. Further elevation is effected automatically by the chains acting through the upper bracket. The lower brackets are then lowered, a fresh board placed on them and a pile built up. When the first pile is nearing exhaustion the second pile is raised manually so that it engages the underside of, and supports the first pile. At a convenient time the first pile board is pulled out allowing the remaining sheets, if any. to fall on the top of the new pile. The process is then repeated as necessary. A rear stacking gauge may be provided extending downwardly from the separator frame passing through a slot in the pile board so that the remaining sheets on the board are controlled as the board is withdrawn. The board is partly withdrawn until the gauge engages the end of its slot and the gauge is then raised vertically to allow the board to be withdrawn completely. The elevating chains may be replaced by elevating screws, the shafts 38 carrying gear wheels meshing with the threads of the screws. Specifications 427,041, 763,831 and 763,833 are referred to.